---It is said that your grandpa was very brave. ---Not .He was than brave. A.exact; cleverer B.exactly; more clever C.exactly; cleverer D.exact; more clever 答案:B“人类基因组计划”需要测定人类的24条染色体的基因及其序列,这24条染色体是( )
A、22条常染色体,再加上X和Y两条染色体B、46条染色体的任意24条染色体C、23条常染色体,再加上X染色体D、23条常染色体,再加上Y染色体